Insulator.



UNITED STATES PATENT OFFICE.

@iRANK r. FOWLE, or CHICAGO, ILLINoi 1s.

INSULATOB.

Specication of Letters Patent.

Pa rented Mar. 2o, 1917.

Application led Hatch 25, 1911. Serial No. 616,714.

which will effectively insulate an electric.

conductor Vfrom its support. Another object is vto provide an insulator' which will have' relatively high tensile strength and insulation resistance, and which can be factured economically. i In the accompanying drawings :--4

Figures 1 and 2 are partial sectional ele manilvations of one form of insulator embodying my invention. Fig. 3 is a view thereof.

Fig. 4 is a perspective view of this form half plan and halfl sectional yof insulator showing one method of suspensuspension. 3'0

illustrates another method of Fig. 6 is a half elevation andd half section of another form of insulator embodying the invention.

` The two forms of insulator illustrated ",-e constructed preferably of porcelain or other suitable material and are adapted more particularly to be used with outdoor conductors suspended above ground upon polestowers or other structures. Thesuspension of com duetors in spans from insulating supports at intervalsl requires' thatl the supports s have suilicient tensile strength to transmit sion. Fig. 5

the mechanical stresses lbetween the con'--` duetor4 and. the main sup-porting structure without' failure, such as fractures, change of s liapej orl cracking, and 'that they shall successfullyfresist the` dielectric stresses with out subetantiul leakage; of current, loss of energy or without arcinig,and furthermore that they shall be offsu'eh material and outlii-"e'as to2 oH- er a very high electrical resistance to the arcin .l or leakage of current through-.or over t el surface thereof. Furtherrrl-orel infractions" should obtain over a wide romige-of variations of temperature and precipitation eand general atmospheric disturbances..

general ,tofrm of insulator illustrated hall in Figs. 1y to 5 inclusive comprises prefer'- ably two main' elements; a hollowshell 1 that is somewhat hemispherical in shape and`- an interior bridge 2, extending from one side of the shell to the'c ther. Between the bridge and the apex of' tlieLshell there is provided a continuous opening or hole 3, leavin a free passage fora wire or cable. The she l 1 and the bridge 2:r'e traversed by a second passage or hole 4 extending entirely through the insulator. Gr oov'edentrances 5, 5, are provided to facilit ite the insertion of a wire or cable through said passage 4, the bottom of which is made substantially straight to prevent the formation of a pocket for water, which if confined therein and frozen might rupture the insulator.

Flaring entrances and grooves 6 are provided within the s aell to facilitate the insertion of the wire or cableby lwhich the conductor is suspended from the insulator.A

One method of supporting the insulator and the conductor, issh'own in Fig.' 4.- The wire or cable 7 "pas ses through the hole 4. and supports the insulator directly while the wirev or cable 8 passes through the'hole 3 and is secured to t ae conductor 9 in any suitable rnanner. VOre satisfactory manner of attaching the wire 8 to the conductor 9 is illustrated in this figure, and consists in wrapping the lover ends of said wire 8 about said conductorV 9 in opposite directions, and then twisting together the ends of 'said wire to prevent unwrapping of the same from the cc nductor. The supporting structural features as 4the 'first form described. 'When i1 is necessary to secure exceedifn-gly high cli-eiectric strength, the insulators'may be huig in series or cascade arrangement as shown inFig. 5, Of course either form of i1 lsulator or 'other modified Vforms thereof ma: f be suspended in this Inan- Iier. With the arrangement of` interlinked loops illustrated, the conductor will be prevented .from falli .ig by 'the loops themselves if the body of the insulatorshould accidentally be broken.

The function cf .the bridge 2, is'to. resist the.` stresses between the t-wo wire loops mainly by its resistance to mechanical compressi, stresses also forms one of the 4dielectric media between these 'loops to resist. puncture orbreak-down from electric stresses. Further, it forms one of the insulating media between the wire loops which 5 minimizes the leakage or escape of current from kthe conductor to the supporting structure above; v "l The function of the shell is to protect the bridge and the supporting wire or cable 8 1`0 ffrom' precipitation of rain, hail, sleet or Snow,.and to'exclude `water or inolsture as' j far as possible.y A further function is to in- '-"tro duce a longrleakage surface for arcing and current escape vfrom one loop. to the other," and' to keep the interior partof this .surface dry'afs far as possible. The insulal tor illustrated injFig. `G is providedwith a "very-'longleakage surface. In both of the forms wh'ich I have illustrated the precipi- -2" tation of; rain. does not wet. or meisten as glial-gea po'rtion'of 'the whole surface between 1 the conductor or the wire and the support which carries the insulator as is the case vwith vother forms of insulators with which I 'am familiar.

j" I desire -tohave it understood that the invention is not limited to the embodiments de- -sci'ibed, as Ithese 'foms were selected-for the` purpose' 'of illustration only. .1I desire there- '30 fore to include all other. suitable and 'equivalent forms which accomplish the desired results Vand fall within the scope of the appended claims.

What I'claim as my invention and desire to secure by 'Letters Patent of the United States is :--v A 1. An insulator comprising a hollow inverted' bowl having 'a bridging member spanning the interior thereof and integral 40 with said Ibowl whereby a continuous passage is formed between said bridge-and the closed end of saidbowl, rooves' on opposite sides of said .bridge to acilitate the inser- 'tion of a cable through said passage, s'aid insulator having a continuous opening therethrough which traverses said bridge and ,terminates in upwardly Haring mouths to per'- "m'it as'upporting cable to be arranged there- 'between said loops.

2. A device of the class described compris- 111g a hollow inverted bowl, a central portion mounted within said bowl and joining the walls thereof at a plurality ofipoints, thereby forming two continuous', V'oppositely directed passagesfor' the-,reception ofcables, 65

one of said passages being entirely housed within said bowl and accessible Vonly from beneath the same, the other of saidpassages terminating in outwardly-Haring mouths on the exterior wall of saidvbowl, and grooves formed in the sides of said central portion and within said first-mentioned passage, substantially as shown and described. In'witness whereof, I have hereunto subscribed my name inthe presence of two witnesses.

FRANK F. FOWLE. Witnessesy A GEO. B. JONES, R. KING.'-

v Copies o! thispatentmay be obtained for live cents each, by addressing the commissioner of Patents,

Washingtom D. C 

